Climate Lab

A latitude-band energy-balance model with ice-albedo and water-vapour feedbacks. Change CO₂, sunlight or Earth’s orbit and watch the climate respond.

Presets

Model speed 20 yr/s

Forcing

CO₂ concentration 280 ppm Sunlight (solar constant) 100% · 1361 W/m² Aerosols / solar dimming 0%

Globe

Season Annual mean

Auto-rotate Warming vs pre-industrial Graticule Animate seasons

Drag the globe to rotate it. Hover for local values.

Scenario

Net-zero year 2050 Year 2025

Solar dimming (aerosol injection) starts in 2040 and ramps up over a decade. Emissions are fossil CO₂ in GtC/yr.

Earth’s orbit

Time 0 kyr ago Eccentricity 0.017 Obliquity (axial tilt) 23.4° Precession (perihelion longitude) 283°

65°N June insolation—

Difference from today—

The orbit sliders feed the climate model too: tilt moves heat between the poles and tropics, and precession shifts the seasons.

Hysteresis

Warm branch collapses below—

Snowball thaws above—

Sunlight changes slowly in the real world, but the same ice-albedo loop applies to CO₂: lowering the sunlight (or CO₂) past the tipping point freezes the planet, and getting it out takes far more warming than getting in.

Model physics

Water-vapour feedback 0.9 W/m²/K Ice albedo 0.62 Heat transport (diffusion) 0.55 W/m²/K

What am I seeing?

Each of the 36 equal-area latitude bands balances absorbed sunlight against outgoing infrared, and heat diffuses poleward. The ocean’s mixed layer sets how fast it responds; a deep-ocean box makes the full response take centuries.
CO₂ reduces outgoing radiation by 5.35·ln(C/C₀) W/m². Warmer air holds more water vapour, which amplifies it. The model’s equilibrium climate sensitivity is measured by running it to equilibrium at 280 and 560 ppm.
Ice-albedo feedback: cold bands grow bright ice, reflect more sunlight and get colder. With enough cooling this runs away to a frozen Snowball Earth, and the loop has hysteresis.
Milankovitch cycles: orbital shape, tilt and precession shift summer sunlight at 65°N. A simple ice-volume model grows ice slowly when summers are weak and melts it faster when they are strong.
This is a simplified teaching model, not a forecast. It has no clouds, no real ocean circulation, no carbon-cycle feedbacks beyond a toy sink, and the land map, sea-level numbers and scenarios are illustrative. Real projections come from comprehensive climate models.